399373 divided by 86 
Our goal is to divide 399373 by 86.

On to step 1:
The number 86 fits into 3 0 times, leaving a remainder of 3.
Write down 0 as next digit of the result. 
Result so far: 0.0
The remainder is 3 after subtracting 0 from 3.
Include the next digit (9) from the dividend after 3, then repeat: 39 / 86

Advancing to step 2:
If we divide 39 by 86, we get 0 and a remainder of 39.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtracting 0 from 39 leaves us with 39.
Append the next digit (9) from the dividend to 39 and continue with: 399 / 86

Advancing to step 3:
399 divided by 86 is 4 with a remainder of 55.
The number 4 becomes the next digit in our result. 
Result so far: 4.0
The remainder is 55 after subtracting 344 from 399.
Bring next digit (3) of the dividend behind the 55 and repeat the process: 553 / 86

Going ahead to step 4:
The number 86 fits into 553 6 times, leaving a remainder of 37.
The number 6 becomes the next digit in our result. 
Result so far: 46.0
If we subtract 516 from 553, we get 37.
Fetch the next digit (7) from the dividend, attach it to 37 and continue: 377 / 86

Let's proceed to step 5:
When dividing 377 by 86, we get 4 with a remainder of 33.
Put 4 as the next digit of the answer. 
Result so far: 464.0
If we take 344 away from 377, we end up with 33.
Grab the next digit (3) from the dividend, add it to 33, then carry on: 333 / 86

Moving on to step 6:
333 divided by 86 is 3 with a remainder of 75.
Use 3 as the next digit of our solution. 
Result so far: 4643.0
Deduct 258 from 333 and we're left with 75.
Since there are no more digits in the dividend, we add a zero to the remainder making it 750, and continue the process.

On to step 7:
If we divide 750 by 86, we get 8 and a remainder of 62.
Put 8 as the next digit of the answer. 
Result so far: 4643.8
Subtract 688 from 750 to get 62.
Since there are no more digits in the dividend, we add a zero to the remainder making it 620, and continue the process.

Going ahead to step 8:
86 can be fit into 620 7 times, resulting in a remainder of 18.
Record the quotient 7 as the next digit in the result. 
Result so far: 4643.87
Subtract 602 from 620 to get 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

Advancing to step 9:
When dividing 180 by 86, we get 2 with a remainder of 8.
Write down 2 as next digit of the result. 
Result so far: 4643.872
Subtracting 172 from 180 leaves us with 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Let's proceed to step 10:
86 goes into 80 0 times with a remainder of 80.
The number 0 becomes the next digit in our result. 
Result so far: 4643.872
Deduct 0 from 80 and we're left with 80.
Since there are no more digits in the dividend, we add a zero to the remainder making it 800, and continue the process.

Moving on to step 11:
If we divide 800 by 86, we get 9 and a remainder of 26.
Put 9 as the next digit of the answer. 
Result so far: 4643.87209
Deduct 774 from 800 and we're left with 26.
Since there are no more digits in the dividend, we add a zero to the remainder making it 260, and continue the process.

On to step 12:
86 goes into 260 3 times with a remainder of 2.
The number 3 becomes the next digit in our result. 
Result so far: 4643.872093
Subtract 258 from 260 to get 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Going ahead to step 13:
86 goes into 20 0 times with a remainder of 20.
The number 0 becomes the next digit in our result. 
Result so far: 4643.872093
Subtracting 0 from 20 leaves us with 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Let's proceed to step 14:
86 can be fit into 200 2 times, resulting in a remainder of 28.
The next digit of our result is 2. 
Result so far: 4643.87209302
If we subtract 172 from 200, we get 28.
Since there are no more digits in the dividend, we add a zero to the remainder making it 280, and continue the process.

After the division, we end up with 4643.87209302 and a remainder of 2.8e-08.